Denon AVR-2805 kicks out

[glemay]

Hey guys, been a while since my last post. I need your thoughts on this problem.

We have the Denon AVR-2805 running a pair of Paradigm Stylus 350 and a pair of Paradigm inwalls, not sure on the model number but they are 6 1/2 inch driver. Now all the speakers are running on small and are crossed over at 80Hz. When playing music at 0.0 on the volume indicator for about 30 minutes the receiver stops playing music.

Is there any reason why this unit should kick out? The unit normally sits in a cabinet but it would kick out so we figured it was the heat. So we pulled it out and it still kicks out when running in the open.

Need your thoughts.

Thanks

Gerald

[aaharvel]

0.0 on the volume indicator?

I don't know about your Denon but for my H/K that is reference level- as in EXTREMELY LOUD.

If this is the case with your Denon- it's prob. not your receiver but the fact that you're clipping your speakers due to the fact the small Paradigms can't take that kind of input. Your Denon is basically just being smart about it and shutting down to prevent further damage to your speakers.

[cfrizz]

TURN IT DOWN! I'm sure your ears, receiver, & speakers will thank you.

[Ricardo]

Originally posted by aaharvel
Your Denon is basically just being smart about it and shutting down to prevent further damage to your speakers.

Is this right? Will the receiver actually "know" speakers are "suffering" and shut down?

I ask because I have a Denon 3803 (110W/Channel) and my side/rear speakers are 100W....when I use 7 channel stereo (normally parties, etc) I have always been very "conservative" on volume to avoid damage.....

(BTW....mine has never kicked out..)

[Mike682]

Just checked some specs for the paradigms and the Denon:

Paradigm:
Amp Range: 15-100w
Max input power: 70w

Denon:
100w x 7ch

Could it be you are feeding those speaks too much power, but not too much that it isn't immediately noticeable?? Paradigm says the range is 15-100w but max power is 70w. I'm thinking the 100w spec insn't meant to be continous.

Also check speaker wires make sure nothing in loose/touching, especially at the back of the receiver..

Hope this helps

[AsSiMiLaTeD]

Uh, 0 on the volume control is insane. I don't know about the efficiency on those Paradigms, but there's no way it's that bad.

You're playing it too damn loud. Reference level on that receiver should be above 0, well above, depending on your setup. Do you have an SPL meter? Measure the volume at your listening position, how loud is it?

I'm gonna go against the grain here and say I don't think you're overpowering your speakers - I think you're just pushing the amps in your receiver beyond their capabilities. You're more likely to get clipping and cause damage by underpowering than overpowering.

All the specs on that receiver and speaker basically don't mean squat, throw another (better) amp on those speakers and I'll bet you can crank it louder...

[glemay]

Too be honest with you guys, 0 on the volume is loud but comfortable seeing as the speakers are setup on the flybridge of our boat. So it is really open and there is very, very little room gain. When at 0 it sounds really clean. I don't hear any clipping or much distorsion, but 30 minutes later it shuts down.

When you're having fun on the boat, you're always playing it loud.:)

[Emlyn]

Both sets of speakers appear to be 8 ohm impedance, around 90 db efficient, so the receiver is capable of running them for long periods, just not at the volume setting used in this application with the internal amp of the receiver. It seems like you need larger outdoor speakers if you need to run the receiver's volume that high on your boat to appreciate the music. Polk makes some good ones as well. If you're determined to keep the speakers you have, you'll need to run them with a separate amplifier to avoid the receiver's thermal shutdown feature being triggered.

These look promising, especially since they can be pointed at the listening area, which may help with the volume control:

Atrium (http://www.polkaudio.com/home/products.php?category=10&speaker=424)

[bknauss]

Couple thoughts:

-The long playing periods at high levels might create a lot of heat and cause the receiver to go into thermal protection.
-The only way to see if the receiver is causing damage to your speakers is to see if you're clipping the signal. If you are clipping the signal, you're definitely likely to over-drive the recevier, cause a lot of heat, and put the receiver into thermal protection.
-I have a feeling (just a feeling, no proof) Denon made that 100Wx7 rating by measuring 1 or 2 channels driven, seeing the 100W, and then magically rating it at 100Wx7. That rating would lead me to believe that all channels driven would give you 100W on each channel, but when you drive all channels (or 4 in your case), you're going to diminish the power output on each channel. This was discussed in the Sony receiver thread.

Did any of that make sense?

[2+2]

Also something to check....if you are running hte 2 pairs of speakers on speaker A and speaker B posts (if the Denon has such a post), your effective impedence is 4 ohms... which reequires a high current amp to drive for long and loud.....

[gregure]

I agree that if you are using A/B speakers at once, you are definitely decreasing wattage and asking too much of the amp at 0 volume level. It is absolutely an issue of heat, as the receiver just doesn't have the sinking for that output. Another amp would solve this problem.
I disagree, however, that Denon plays the wattage game that Sony plays. Denon uses discrete output amp construction, and their ratings are accurate, unlike Sony and Onkyo (although at least Onkyo puts the truth in the fine print-ie 100 watts RMS into 8 Ohms, two channels driven).
Definitely overdriving the poor Denon in this case. Seek a greater method of amplification and ye shall find a solution.

[aaharvel]

Originally posted by bknauss
I have a feeling (just a feeling, no proof) Denon made that 100Wx7 rating by measuring 1 or 2 channels driven, seeing the 100W, and then magically rating it at 100Wx7. That rating would lead me to believe that all channels driven would give you 100W on each channel, but when you drive all channels (or 4 in your case), you're going to diminish the power output on each channel. This was discussed in the Sony receiver thread.

I would be very disappointed in Denon if they did this. Really disappointed.

[Mjr7531]

There's a law about rating the amps, in stereo, no one has updated it yet, sad but true, so they can rate it how they wish.
Many companies rate each channel at 1 kHz, and go through every one, sometimes even at 6 ohms for a boost *cough* Sony *cough*. However, for their stereo specs, they MUST do the 20 to 20 two channels driven. They're kinda cheating aren't they? :rolleyes:

[bknauss]

The law is possibly being upgraded for the 21st century.

Comparing what Sony does to my suggestion of what Denon *might* do is two completely seperate worlds. There's a difference between Sony saying "each channel put's out X power when in stereo, but put's out about a quarter of that with all channels driven" and what others due with "each channel put's out X power when in stereo, but does better than half of that when all channels are driven". One is a small power supply issue while the other one is just cutting corners!

[McLoki]

Originally posted by HTrookie
Is this right? Will the receiver actually "know" speakers are "suffering" and shut down?

No, the reciever will not monitor the speaker and shut down due to its response. It can shut down if driven to hard and it overheats. Usually the speaker has protection built into it for clipping, not the amp. (the amp may have lights or some such thing though)

I would recommend an external amp to run for parties. It will sound much better and put out decent sound all day if you want to. Just a thought.

Michael

[Ricardo]

Originally posted by McLoki
No, the reciever will not monitor the speaker and shut down due to its response. It can shut down if driven to hard and it overheats. Usually the speaker has protection built into it for clipping, not the amp. (the amp may have lights or some such thing though)

I would recommend an external amp to run for parties. It will sound much better and put out decent sound all day if you want to. Just a thought.

Michael

Thanks Mike, that's what I thought; my 3803 has never had any problems playing at "0" for extended times, (though I've not done this on 7 Ch stereo...).

I also went through the separate amps option (3 outlaw 200M for fronts and center), but did not really notice a difference worth the extra money and decided to use their 30 days money back option...

[unc2701]

Originally posted by gregure
I disagree, however, that Denon plays the wattage game that Sony plays. Denon uses discrete output amp construction, and their ratings are accurate, unlike Sony and Onkyo (although at least Onkyo puts the truth in the fine print-ie 100 watts RMS into 8 Ohms, two channels driven).

Maybe, but something DOES NOT add up: "Power consumption: 5.6A" so that's 672 watts. Ignoring all the overhead and heat that thing is throwing off, that's still less than 100 watts per channel. In fact, once you take into account the usual overhead, it works out to something like 25-30 watts per channel.

[aaharvel]

Originally posted by unc2701
Maybe, but something DOES NOT add up: "Power consumption: 5.6A" so that's 672 watts. Ignoring all the overhead and heat that thing is throwing off, that's still less than 100 watts per channel. In fact, once you take into account the usual overhead, it works out to something like 25-30 watts per channel.

well now i'm disappointed in Denon. Hey UNC2701 would you consider looking up that kind of info for a H/K 235? I'm not that knowledgable. ;)

[unc2701]

H/K 235:
Maximum power consumption: 890W (7 channels driven)

Now that doesn't mean that the HK is better than the denon- it just means that it is physically possible for the HK specs to be true.

So either that Denon's 5.6 amps isn't its max consumption or what they mean by those specs is that each channel could do 100 watts, with no others driven.

Max power consumption is one more way to see through manufacturer's bullshit specs. If it's truly 100w x 5, it should be over 15amps/ 1800 watts.

[aaharvel]

Originally posted by unc2701
H/K 235:
Maximum power consumption: 890W (7 channels driven)

Max power consumption is one more way to see through manufacturer's bullshit specs. If it's truly 100w x 5, it should be over 15amps/ 1800 watts.

So basically yeah the 235 is right there with its claimed spec of 50x7- (if you divide the 100watt receiver/1800 by 2)

Hey thanks UNC- very helpful.

[Ricardo]

Originally posted by unc2701
If it's truly 100w x 5, it should be over 15amps/ 1800 watts.

How do you get to this? I am not an expert on audio equipment...and I have no idea if the output watts should be equal, lower or greater than the input watts...... but in my mind required consumption for a 100w x 5 should be closer to 500W/4.2 amps than 1800W/15 amps....

Txs.

[unc2701]

Depending on your amplifier design, you're going to have varying efficiencies, however, your typical class A/B design is going to need about 4 times the input wattage to get the rated output wattage into 8 ohms. In a lot of recievers, the limiting factor is the power supply. Each individual amp is capable of 100 watts, but the power supply can't supply all those watts for all the channels.

Now, you can't do a model to model line up based on the max power consumption, but you can use it as a BS detector. You CANNOT put out more watts than you put in... or even equal watts (all that heat has to come from somewhere- in fact that's where most the additional wattage goes). If the max consumption is less than what the maker says it can ouput, then you know they're full of crap.

[Ricardo]

Originally posted by unc2701
Depending on your amplifier design, you're going to have varying efficiencies, however, your typical class A/B design is going to need about 4 times the input wattage to get the rated output wattage into 8 ohms. In a lot of recievers, the limiting factor is the power supply. Each individual amp is capable of 100 watts, but the power supply can't supply all those watts for all the channels.

Now, you can't do a model to model line up based on the max power consumption, but you can use it as a BS detector. You CANNOT put out more watts than you put in... or even equal watts (all that heat has to come from somewhere- in fact that's where most the additional wattage goes). If the max consumption is less than what the maker says it can ouput, then you know they're full of crap.

Well, if what you are saying is right, then Denon IS full of crap????

Checked a few specs on both brands and in general power consumption is close to double in HK for the same output watts.....

Hard to believe......anyway.....I'm still happy with the sound of my Denon.

Hmmmmm... maybe HK is using BS specs going so high...
:D :D :D

[unc2701]

Well, it is possible that the Denon power consumption is not the maximum, but the consumption at, say 1 watt. Regardless, that Denon only has one power supply, so the all channels driven wattage has to be less than the single channel driven.

[Mike682]

Ok...let's get rid of all the channels and look at a monoblock amp. The Outlaw M200 is rated at 200w/ch @ 8ohms and consumes 600 watts max.

Keep in mind this is a dedicated amp with one transformer supplying one channel and nothing else, no pre-amp/pro, no tuner as in the case of a receiver.

The 600watts sounds about right from unc2701's post regarding the equation : input wattage x ~4 = output wattage for A/B amps. Since the mono outlaw runs A/B until 80w then switches to G, looks like they are very close. If it was 100% A/B, I wonder if Outlaw would have increased consumption (larger power supply)to compensate for loss due to heat, etc??

Just wondering

[TheReaper]

Originally posted by HTrookie
Hmmmmm... maybe HK is using BS specs going so high... :D :D :D
My friend and I were pondering the high HK AV630 max power consumption, considering the a/c input on the back states 550W.

From the HK AVR630 manual:

Power Consumption 59W idle, 1000W at rated power output (7 channels driven)

From the back of the HK AVR630:

AC INPUT ~120V/60hz 550W

[bknauss]

Originally posted by unc2701
Well, it is possible that the Denon power consumption is not the maximum, but the consumption at, say 1 watt. Regardless, that Denon only has one power supply, so the all channels driven wattage has to be less than the single channel driven.

All current specs on the back of electronics are for maximum current draw before the fuse blows. So in essence, whatever 120 * I is, is the max power consumption.

[bknauss]

Originally posted by unc2701
Depending on your amplifier design, you're going to have varying efficiencies, however, your typical class A/B design is going to need about 4 times the input wattage to get the rated output wattage into 8 ohms.

I'm confused... you can't magically create power. If simple math shows you're going to have the receiver/amp pull X amount of watts, you'll probably get 50-60% of that as your total output power of the system.

[audiobliss]

Wow...all of this is really getting me curious. The Outlaw 200M monoblocks are class A/B until 80 watts and then it switches to class G? Is that right? I've never even heard of class G.

UNC2701....buddy...ol' pal.....:D Could you figure out what my Yammy RX-V1400 will really do and how far off it really is? I'd be interested to see. And actually, this could be kinda cool. We've already discovered how off a Denon is, and an H/K. Now we can figure out a Yamaha. Then maybe an Onkyo would be good.

Thanks!

[Mike682]

Originally posted by audiobliss
Wow...all of this is really getting me curious. The Outlaw 200M monoblocks are class A/B until 80 watts and then it switches to class G? Is that right? I've never even heard of class G.!

At first, I thought it was C but it's G..

From Outlaw's site:

Q. Any other specifics?
A. The Model 200 utilizes a newly designed (and proprietary) hybrid Class A/B/G circuit. It will provide Class A/B power up to 80 watts (which covers about 98% of most listening situations). Above 80 watts the Model 200 will instantly shift into Class G amplification.

Q. Why was this approach taken?
A. This approach was chosen because we required that this amplifier be quite compact (less than 2 inches tall). In addition we insisted that the amplifier would not use any fans.

Q. Are there any downsides to this type of hybrid design?
A. The 200 uses a proprietary A/B G design that does not have any audible downsides. The transition from Class A/B to Class G requires just 2 microseconds (NOT milliseconds) and this transition is 100% inaudible. This was imperative as many other hybrid designs produce audible side effects. Incidentally, at 200 watts the 200 has less than .05% THD!

Q. What about output transistors and capacitance?
A. For output devices there are a total of six: four bipolar transistors rated at 15 amps each, and two robust power Mosfets rated at 40 amps each. Dynamically into 8 ohms the 200 will put out 300 watts! In addition it has at its disposal 20,0000 microfarads of capacitance.

[Mike682]

Originally posted by audiobliss
We've already discovered how off a Denon is, and an H/K. Now we can figure out a Yamaha. Then maybe an Onkyo would be good.

Actually, HK has been pretty close to spec in reviews regarding output w/all ch driven.

[audiobliss]

Originally posted by Mike682
Actually, HK has been pretty close to spec in reviews regarding output w/all ch driven.

Indeed, it has. Not to sound defensive or anything, but I just stated that we found 'actual' outputs on Denon, H/K, Sony, etc. I didn't make any comments on what it was we found.

And, actually, there wasn't much of a 'we' about it, lol. I didn't do anything but read it! :D

[cfrizz]

Just get receivers with pre-outs so you can buy separate amps when you need more power!:rolleyes: :p ;) :D

[shiu]

unc has said more than once that the Denon's power consumption may not be maximum. For those who own a 3803, 05 etc., take a look at the back or the manual, they do not say it is "maximum". Why insist it is? As for HK, they clearly stated the 890W for the 235 is "maximum" but they did not say whether it is a continuous rating.

I am not sure about the 2805 but in my 12X18X8 room, I get 75 dB at 13' away from my speakers (87 dB sensitivity), with the 3805 volume set to 0. It is way too loud and I am not surprise the amp would trip after 30 min.

[Ricardo]

Originally posted by TheReaper
My friend and I were pondering the high HK AV630 max power consumption, considering the a/c input on the back states 550W.

From the HK AVR630 manual:

Power Consumption 59W idle, 1000W at rated power output (7 channels driven)

From the back of the HK AVR630:

AC INPUT ~120V/60hz 550W

Hmmmm.........:rolleyes: :rolleyes: :rolleyes: :rolleyes: :rolleyes:

[audiobliss]

The back of my Yammy says:

120V 500watts
630VA 60Hz

[Toxis]

Originally posted by TheReaper
1000W at rated power output (7 channels driven) OH S**T! It's a 1000 WATT? DAAAAAAAMN!

[audiobliss]

ROFL

[glemay]

Well thanks for your thoughts guys. A friend gave me two small fans to help cool the receiver. If I plug in on the trigger on the back of the receiver, will I just keep taking more power from the unit or should the fans on the trigger be fine?

Thanks

[unc2701]

1000 watts... hehe.

Anyhow, take all this with a grain of salt- don't turn it into your new spec to look for. Just be suspicious if the rated power somehow excedes the maximum power consumption.

On the other flip side of this (and why the manufacturers can get away with it)- for most 7 channel applications, you don't need full rated power going to all the speakers at the same time; the fronts rarely hit at the exact same time as the rears.

glemay: there should be a tigger amperage rating on the back of the amp or in the specs and an amperage on the fans- if the ones on the fans add up to more than the trigger rating (very likely), just get a 12v wallwart and plug it into the switched outlet on the back of the reciever.

edit:Yeah, deffinitely get a wallwart to run 'em- those tiggers are only rated for 25mA each, and most computer fans pull over 100mA.

[shiu]

One good thing about HK, they are more specific, examples: they give you the consumption at idling, 2 ch. driven power, 7 ch. driven power, instantaneous current, and maximum power consumption. Look at Denon's spec, no 5 or 7 channel driven power output, no instantaneous current values, yet they do claim "high current capability", and no maximum power consumption, just power consumption, so you cannot even calculate backward. May be they want people to think they cost less in electricity.

If you have to run a mid level receiver at "0", an external fan is a great idea. I think all HK models (may be except for the flag ship model) are equipped with an internal fan. The Denon 3805 does not have a fan. I doubt the 2805 has one.

[John K.]

Two questions, relating to power ratings and power consumption, have been discussed here. On the matter of the listed power consumption, it should be noted, as was suggested, that the consumption figure isn't a maximum figure(unless language such as "maximum", "full power, all channels driven", etc. is specifically used). In general the number shown is an average(rather than maximum)consumption figure, and typically the average is calculated on the basis of all the channels being driven at 1/8th of the rated maximum power. The 1/8th standard is used by safety testing organizations such as Underwriters Laboratory as a requirement for continuous operation without overheating, and represents the approximate average power needed from amplifiers over a long time period in playing music which varies from a very low level to one requiring the maximum power output. While a typical class AB amplifier is roughly 50% efficient( about 80% for the power supply section, about 60% for the amplification section)at full power, at lower power levels efficiency is much less, in the area of 20% or even lower. The bottom line here is that there's no inconsistency when the 7x100 watt amp has a label showing 500 watts consumption. The figure isn't derived using 700 watts output, but rather 1/8th of that, i.e. about 88 watts, reflecting an efficiency of under 20% at that power level. Likewise a maximum power consumption figure is derived using full power and about 50% efficiency.

On the question of the accuracy of published power ratings, it's somewhat ironic that while some are willing to take seriously bizarre claims about the "sound" of amplifiers, players and even wires which have no factual basis, they view with suspicion the only area of audio in which there are fairly specific federal regulations which a manufacturer would be foolish to violate. The FTC regulations (http://www.washingtonwatchdog.org/documents/cfr/title16/part432.html) define the procedure for arriving at the power rating. It should be noted that contrary to the misconception that the rating has to be with all channels driven, the actual requirement is for all "associated" channels to be driven. When the reg came into effect in 1974 there were very few amps with more than two channels and "associated" was considered to mean two stereo channels. This is still the view today, although as shown in this FTC Notice (http://www.ftc.gov/os/2000/12/amplifierrulenotice.pdf) more specific multi-channel requirements were to be considered about five years ago. No action has resulted, although the FTC has left the matter open. So, all manufacturers arrive at their power ratings in compliance with the FTC procedure and the great majority(Denon, Onkyo, Yamaha, etc.)arrive at it by driving two channels simultaneously. Of course, manufacturers have the option to specifically use a figure with all channels simultaneously driven at full power for five minutes(although this isn't a realistic scenario for home use)and some, e.g. HK, do this; but whatever the case may be published amplifier power ratings can be relied upon as being accurate.

[shiu]

John, whether what you stated are right or not, it seems to make logical sense. Another ironic thing is that while HK rates their power outputs relatively lower than their competitors within the same price group, many believe they are actually more powerful because they rate their outputs conservatively. Yet, if you look at some of the lab measurement results S&V, HT mag etc., they are in line with other leading brands such as Denon, Yamaha, Pioneer, and even Sony (not the DE series of course) when tested under the same conditions. Isn't it true that honesty is the best policy.

Sorry about getting off topic.

[bknauss]

John - there is currently an initiative with CEA to revise the testing procedure and marketing claims of power from receivers. CEA is hoping the standard will be accepted by the FTC and become not only a standard, but law.

It should be stated that companies like Denon are posting power ratings based on standards/rules/laws, but it doesn't mean they are posting what reality is. The FTC link provided by John says (in summary): you get rated power by applying a signal to the aux input of the receiver (*cough* TWO CHANNEL *cough*), make sure it doesn't go above a certain THD threshold, and measure the power output during a 5 minute span. Since there is no mention of using all aux inputs possible, you can read it as measuring two channels and deriving the power output of the rest of the channels from that by simply hitting "copy" and "paste". You can thank marketers everywhere for stuff like this :)